Related for Kiddushin 149:10
ודאן בודאן מותר אמר רב יהודה אמר רב הלכה כרבי אליעזר כי אמריתה קמיה דשמואל אמר לי הלל שונה עשרה יוחסים עלו מבבל וכולם מותרים לבא זה בזה ואת אמרת הלכה כרבי אליעזר
CERTAIN [UNFITS] ARE PERMITTED [TO INTERMARRY] WITH CERTAIN [UNFITS]. Rab Judah said in Rab's name: The halachah is as R'Eleazar. When I stated it before Samuel, he observed to me, Hillel taught: Ten genealogical classes went up from Babylon and all are permitted to intermarry;<span class="x" onmousemove="('comment',' Rashi: 'all' means the forbidden classes; Tosaf. explains: each category is permitted to marry within itself; on both views 'doubtful' may intermarry with 'doubtful,' thus disagreeing with R. Eleazar. - On 'Hillel taught' both Rashi and Tosaf. Ri observe: in the Baraitha based on this Mishnah of 'TEN GENEALOGICAL CLASSES'. Weiss. Dor. I, p. 175 (1924 ed.) conjectures that this might have been taught when Herod destroyed the ancient Book of genealogical records, of which this may be an extract. (The verb shanah employed here generally refers to a Mishnah, not a Baraitha.)');"><sup>13</sup></span>